These guns were fitted to many battleships and battlecruisers completed just before and after the start of World War I. When compared to contemporary British guns in terms of penetrating power, they were superior to the 12"/45 (30.5 cm) and 12"/50 (30.5 cm) guns, and only slightly less powerful than the 13.5" (34.3 cm) guns. They were, of course, completely outclassed by the 15"/42 (38.1 cm) guns used on the Queen Elizabeth class.
The battlecruisers Derfflinger and Lützow used these weapons at the Battle of Jutland (Skagerrak) to sink the British battlecruisers HMS Queen Mary and HMS Invincible.
The World War I Coastal Defense Battery Kaiser Wilhelm II located near Knocke in Belgium was equipped with four of these guns.
The mountings for these guns used electric pumps to drive hydraulic elevation gear while the training was all electric. These guns also had hydraulically worked rammers and breeches, the first fitted to German large-caliber guns. These changes increased the rate of fire, with most ships having a ROF of 20 seconds while the Kaiser class were reported to have had an overall ammunition supply speed of three rounds in 48 seconds, including all transfers.
In World War II these guns were used only as coastal artillery. They were then supplied with a more streamlined shell and used a larger propellant charge, giving them increased range. The best known battery was the six-gun Friedrich August at Wangerooge. Later, three of these guns on BSG mountings were moved to near Wimille on the Channel Coast.
Constructed from shrunk on tubes and hoops and used the Krupp horizontal sliding wedge breech block.
Actual bore diameter was 30.50 cm (12.008").
|Designation||30.5 cm/50 (12") SK L/50|
|Ship Class Used On||Helgoland, Kaiser, König and Derfflinger Classes|
|Date Of Design||1908|
|Date In Service||1911|
|Gun Weight||114,309 lbs. (51,850 kg) 1|
|Gun Length oa||600.4 in (15.250 m)|
|Bore Length||569.3 in (14.461 m)|
|Rifling Length||465.0 in (11.805 m)|
|Grooves||(88) 0.262 in D x 0.118 in W (6.68 mm D x 3.0 mm W)|
|Lands||0.165 in (4.20 mm)|
|Twist||Increasing RH 1 in 45 to 1 in 30 at the muzzle|
|Chamber Volume||For 551 lbs. (250 kg) shells: 12,052 in3 (197.5 dm3)
For 892.9 lbs. (405 kg) shells: 12,205 in3 (200.0 dm3)
|Rate Of Fire||2 - 3 rounds per minute|
- ^The often-seen figure of 171,079 lbs. (77,600 kg) for this weapon actually includes the weight of the Weige (gun cradle).
|Type||Cartridge - Bag|
|Projectile Types and Weights 1 2||
|Propellant Charge 4 5||
|Muzzle Velocity 6||
|Working Pressure||20.9 tons/in2 (3,300 kg/cm2)|
|Approximate Barrel Life||200 rounds|
|Ammunition stowage per gun 7||Helgoland: 85 rounds
Kaiser: 86 rounds 8
König 9 and Derfflinger 10 : 90 rounds
Diagrams of some of these projectiles and their fuzes and propellant charges may be found below.
- ^APC shells were painted blue, HE yellow and Training red. A black painted nose indicated that the shell was armed.
Actual designations for World War I Projectiles APC L/3,4 Psgr. L/3,4 (mhb) HE L/3,8 Spr.gr. L/3,8 Bdz Actual designations for World War II Projectiles APC L/3,4 Psgr. L/3,4 (mhb) HE L/3,8 Spr.gr. L/3,8 Bdz Actual designations for World War I Projectiles APC L/3,4 Psgr. L/3,4 (mhb) APC L/4,9 Psgr. L/4,9 (mhb) HE L/3,8 base fuze Spr.gr. L/3,8 Bdz HE L/5 base fuze Spr.gr. L/5 Bdz HE L4,8 nose fuze Spr.gr. L/4,8 Kz HE L/3,6 base and nose fuze Spr.gr. L/3,6 Bdz u. Kz (mhb)
- ^"German Battlecruisers of World War One" says that the HE L3,8 weighed 914.9 lbs. (415 kg), all other references quote a weight around 892.9 lbs. (405 kg). As these projectiles used a base fuze and a thick nose wall, they should be considered more equivalent to SAP rounds. These rounds could penetrate 6 to 20 feet (2 to 6 m) through unarmored structures before detonating.
- ^These guns, like most large caliber German guns of this era, used a "fore charge" which was propellant in a double bag silk case and a "main charge" which was propellant in a brass case. The brass case helped to seal the breech of the gun.
- ^I lack the break down between fore and main charges for the 1942 propellant charges.
- ^Using the "Small Battle Load" of just the main charge gave a muzzle velocity of about 2,034 fps (620 mps).
- ^Outfits were typically 70% APC and 30% HE.
- ^British post-war documents claim that the Kaiser class carried 98 to 103 rounds per gun.
- ^British post-war documents claim that the König class carried 96 to 100 rounds per gun.
- ^Outfit for Derfflinger class was 65 APC and 25 HE per gun.
|45.0 degrees||35,000 yards (32,000 m)|
|49.2 degrees||45,166 yards (41,300 m)|
|50.0 degrees||43,200 yards (39,500 m)|
|49.1 degrees||56,200 yards (51,400 m)|
- ^The data for the 915 lbs. (415 kg) APC L4,9 shell is from two different sources, which may account for the large difference in range for only a slight change in elevation.
- ^The APC L/4,9 shell had a significantly better ballistic shape than the previous ones. It is noted as being "of longer range" than the older APC, which I take to mean that the newer projectile would have had a longer range when fired at the same elevation.
|Range||Side Armor||Deck Armor|
|14,000 yards (12,800 m)||10.0" (254 mm)||---|
|16,000 yards (15,000 m)||9.0" (229 mm)||---|
Data from "Jutland: An Analysis of the Fighting."
|Range||Side Armor||Deck Armor|
|10,940 yards (10,000 m)||13.6" (345 mm)||---|
|13,120 yards (12,000 m)||12.0" (305 mm)||---|
Data from "German Battlecruisers of World War One."
|Weight||Ships: Between 534 to 549 tons (543 to 558 mt) 4
Coastal Artillery/: 271.9 tons (276.26 mt)
(see Note 4)
|All ships as built: -8 / +13.5 degrees
After 1915: -5.5 to +16.0 degrees 6
Coastal artillery: -5 / +50 degrees
|Elevation Rate||Ships: 4 degrees per second
Coastal Artillery: 10 degrees per second with shell loaded
|Train||End Turrets: About +150 / -150 degrees
Beam Turrets: About +80 / -80 degrees
Coastal Artillery: -220 / +220 degrees
|Train Rate||Ships: 3 degrees per second
Coastal Artillery: 4 degrees per second
|Gun recoil||36.0 in (91.5 cm) 7|
|Loading Angle||Ships: about +5 degrees
Coastal Artillery: 0 degrees
Run out was by compressed air. Magazines were below shell rooms on the battleships.
On the Derfflinger class except for Hindenburg, A, B and C turrets had the magazines below the shell rooms, but D turret had the magazine above the shell room for reasons of space. D turret also did not have the shell hoists broken at the working chamber as did all other 30.5 cm (12") mountings. Instead, the projectile hoist ran directly from the shell room up to the gunhouse. Hindenburg had all shell rooms below the magazines as in the battleships. Hindenburg also differed from her half-sisters by having LC/1913 mountings with half the number of hoists as the the LC/1912, but these hoists ran faster and were still capable of supplying the equivalent of three complete rounds per gun per minute. The LC/1913 turrets had 7.7 m (25.5 foot) rangefinders on each turret rather than 3 m (10 foot) rangefinders on earlier designs. The Helgoland, Kaiser and König classes had a machinery level directly below the gunhouse with a handling room below it. Lower shell and projectile hoists came up to this room and the ammunition was then transferred over to upper hoists which ran up to the gunhouse. Battlecruisers were similar except for Hindenburg in which the projectile hoists ran directly up to the gunhouse although the propellant hoists were still two-stage.
Training of the gun turrets was electric and gun elevation was hydraulic. Hydraulic power was provided by two electrically-driven triple pumps. Rammers were hydraulically powered with fluid being supplied directly from the elevation pump. Wedge breech mechanisms were hydraulically powered but could be manually operated.
Propellant smoke was removed with two independent suction systems, each with its own motor. Should one motor fail, the other motor could be coupled to run both systems at a reduced rate.
For at least the Drh LC/1912 turrets, the guns were separated by a 25 mm (1.0") splinter bulkhead. Following the Dogger Bank action, German mountings were modified to improve flash precautions. Double flap doors were installed at the beginning and end of the cartridge hoist and ready ammunition was removed from the gun houses.
The gun axes were (270 cm) apart.
- ^The Kaiser class were the first German battleships to have superfiring turrets. This allowed them to have one less turret than previous classes (5 vs. 6) yet still be able to fire the same number of guns on the broadside.
- ^The König class had all main guns on the centerline, giving them a heavier broadside than earlier ships.
- ^Derfflinger had a crew of 70 men in C mounting and probably in A and B as well while D mounting had 80 crewmen.
- ^The mounting weight differences were mainly the result of thicker armor used on the battleships.
Armor thickness given in "Naval Weapons of World War One" by Norman Friedman Battleships Battlecruisers Face 11.8 in (30 cm) 10.6 in (27 cm) Sides 9.8 (25 cm) 8.7 in (22 cm) Rear 11.4 in (29 cm) except Kaiser class: 10.6 in (27 cm) 10.6 in (27 cm) Roof 3.1 to 4.3 in (8 to 11 cm) except Helgoland class: 2.8 3.9 in (7 to 10 cm) 3.1 to 4.3 in (8 to 11 cm) except Hindenburg: 3.1 to 5.9 in (8 to 15 cm)
- ^Prinzregent Luitpold was modified just before and the other ships shortly after Jutland (Skagerrak) to increase the maximum elevation from +13.5 to +16.0 degrees. A few sources claim that the maximum elevation was increased on all ships to 16.5 degrees rather than to 16.0 degrees. Norman Friedman in "Naval Weapons of World War One" gives conflicting data for maximum elevations and ranges with no explanation. For that reason, I do not believe this source to be a reliable reference in this matter.
- ^The recoil distance given above is the nominal figure. The absolute, metal-to-metal recoil distance was 38.6 inches (98.0 cm).
- "The Battle of Jutland" by Geoffrey Bennett
- "Warship Special 1: Battle Cruisers," "Jutland: An Analysis of the Fighting" and "Naval Weapons of World War Two" all by John Campbell
- "Battleship Design and Development 1905-1945" and "Naval Weapons of World War One" both by Norman Friedman
- "German Warships 1815-1945" by Erich Gröner
- "The Big Gun: Battleship Main Armament 1860-1945" by Peter Hodges
- "The German Defenses on the Coast of Belgium" by Lt. Col. H.W. Miller USA in "The Journal of the American Society of Mechanical Engineers" Vol. 42, No. 6, June 1920
- "North Sea Battleground: The War at Sea 1914-18" by Bryan Perrett
- "Die Geschichte der deutschen Schiffsartillerie" by Paul Schmalenbach
- "German Battlecruisers 1914-18" and "German Battlecruisers of World War One" both by Gary Staff
- "German Warships of World War I" by John C. Taylor
- "German Capital Ships of World War Two" by M.J. Whitley
- M.DV.Nr.170,54 "Merkbuch über die Munition der 30,5 cm SK L/50 der Marine-Küstenartillerie" Berlin 1940, Oberkommando der Kriegsmarine
- M.DV.Nr. 234.6 "Vorläufige Beschreibung der 28 cm S.K.L/45, 28 cm S.K.L/50 und 30,5 cm S.K.L/50 in Kst.Drh.L.C.37" Berlin 1941, Oberkommando der Kriegsmarine
Special help from Peter Lienau
- 28 December 2008
- 18 November 2010
- Corrected typographical error, modified some picture captions for clarity
- 26 August 2011
- Added twist and projectile information
- 21 December 2011
- Added picture of shell that hit HMS Defender
- 31 December 2011
- Added mounting notes and source for picture on Additional Pictures page
- 24 November 2012
- Added details on mountings
- 08 December 2014
- Added comment on HE Shell weight, additional armor penetration data, additional information on mountings
- 29 August 2015
- Additional ammunition and mounting information
- 17 April 2016
- Corrected typographical error